6T-CEM Cells

The 6T-CEM cell line is a mutant derivative of the human acute lymphoblastic leukemia (ALL) T-cell line CCRF-CEM. It was developed by exposing the parent CEM cells to 6-thioguanine, leading to the selection of a subline that exhibits resistance to this compound. This resistance is a result of the inactivation of the HPRT gene, which is critical in the purine salvage pathway. The 6T-CEM cells have been particularly valuable in studying drug resistance mechanisms, especially concerning purine analogs like 6-thioguanine. Additionally, these cells are characterized by their secretion of a unique T-cell suppressor inducer factor (SIF), which is not only non-mitogenic and non-cytotoxic but also capable of suppressing T-cell proliferation while sparing B-cell proliferation at certain dilutions. 6T-CEM cells and their subclones, like 6T-CEM-20, have shown a significant increase in the production of this suppressor-inducer factor, which has potential applications in immunological research, particularly in the study of T-cell regulation and immune suppression. The SIF secreted by these cells has been shown to suppress up to 90% of mitogen-induced T-cell proliferation at extremely high dilutions (up to 10^-9), making these cells a potent model for exploring therapeutic strategies that involve modulation of the immune response. The use of these cells in various experimental setups has provided insights into the molecular underpinnings of immune suppression, with potential implications for the development of treatments for autoimmune diseases and in the context of organ transplantation to prevent graft rejection.